Reciprocable type carrier with individually movable type bars



1967 N. E. F. HOLMQVIST 3,301,178

RECIPROCABLE TYPE CARRIER WITH INDIVIDUALLY MOVABLE TYPE BARS Filed Feb. 24, 1965 2 Sheets-Sheet 1 1967 N. E. F. HOLMQVIST 3,301,178

RECIPROCABLE TYPE CARRIER WITH INDIVIDUALLY MOVABLE TYPE BARS 2 Sheets-Sheet 2 Filed Feb. 24, 1965 United States Patent Ofiice 3,301,178 Patented Jan. 31, 1967 3,301,178 RECIPROCABLE TYPE CARRIER WITH INDIVIDUALLY MOVABLE TYPE BARS Nils Evert Fridolf Holmqvist, Malmo, Sweden, assignor to Aktiebolaget Addo, Malrno, Sweden, a corporation of Sweden Filed Feb. 24, 1965, Ser. No. 434,987 Claims priority, application Sweden, Feb. 27, 1964, 2,402/ 64 4 Claims. (Cl. 101-409) This invention relates to a printing unit having at least one type carrier which is reciprocable in a frame in a definite path to set into printing position a type bar selected from several type bars mounted in the carrier in a row in parallel beside each other and movable in their longitudinal direction in relation to the carrier transversely of the path thereof, said type bars each carrying at one end a printing type which, when the respective type bar is set into printing position, can be pressed from an inoperative position against a support by means of a printing hammer moving the respective type bar against spring action.

Such printing units are useful in many different connections, such as in listing calculating machines, bookkeeping machines, read-out devices for data processing machines, recording measuring instruments etc.

In a prior-art type of printing unit of the above men tioned kind the printing bars are provided each with one spring disposed in the carrier for resiliently retaining the type bars with the types in the inoperative position. This device isexpensive to manufacture and to mount and does not permit reducing the spacing in a line printed by the printing unit under a certain relatively large measure, without jeopardizing the mechanical strength of the various printing unit details. Some improvement in the respects outlined can be attained by making use of another prior-art construction in which the type bars are retained with the types in the inoperative position by means of a hairpin spring disposed in the carrier and common to the type bars, but in this case one also has to take into account the' drawbacks that at least the type bars located closest to the type bar occupying printing position lose during printing theirengagement with the spring and as a result have the possibility of effecting uncontrollable shifting movements, and that the spring actuates the varous type bars with an unequally large force with the entailing risk that the print will have irregular density.

The invention has for its object to eliminate the drawbacks outlined above inherent in the prior-art constructions of printing units of the type indicated in the foregoing. The invention is substantially characterized in that the type bars are adapted, during the movement of the carrier in its path, to be retained with the types in the inoperative position by a guide which is disposed on the frame, which extends substantially in parallel with the carrier path and consists of two parts stationary in relation to the frame located on either side of the printing position, and of a portion of a yielding means which portion is disposed in the printing position and adapted resiliently to yield when the type bar set into printing position is moved by the printing hammer.

In the printing unit according to the present invention the non-printing type bars are safely retained with their types in inoperative position during printing so that they cannot effect any uncontrollable shifting movements. Besides the same spring force is always obtained for all type bars. The printing unit according to the invention also permits printing at considerably smaller spacing than do the prior-art printing units without reducing the mechanical strength of the details. Furthermore, the printing unit according to the invention is extremely simple and easy to assemble.

These and further objects of the invention will become apparent from the following description in which reference is made to the accompanying drawings diagrammatically illustrating an embodiment of the printing unit.

In the drawings:

FIG. 1 is a longitudinal section of a printing unit, a cover plate for type bars on a carrier being broken away for greater clarity;

FIG. 2 is part of a cross section of the printing unit on line Il-II in FIG. 1;

FIG. 3 is a side elevation of a detail;

FIG. 4 is a view of a modification.

The printing unit chosen by way of example is a digit printing unit comprising several decades which are mutually alike and one of which is shown in side elevation in FIG. 1. Each decade has a type carrier 1 consisting of pressed sheet metal and having one end connected through a rod 2 to a setting register not shown, e.g. of the conventional type used in listing calculating machines. Ten positioning grooves 3 are pressed into the carrier 1 both at the upper and the lower edges thereof (see FIG. 1). Fitting longitudinally movably into each pair of these grooves 3 is a type bar 4 which carries a printing type 5 at its lower end as viewed in FIG. 1. Thus the carrier 1 comprises ten type bars 4 mounted in a row in parallel beside each other, viz. one type bar for each of digits 09 although only some of the type bars have been shown in FIG. 1 to avoid crowding of the drawing. The type bars are retained in engagement with their grooves 3 by a cover plate 6 shown only in FIG. 2 and secured to the carrier 1 so that the type bars are freely movable longitudinally in relation to the carrier. FIG. 1 shows the type bar 4 for Zero to the far left occupying a printing position in which the type 5 pertaining to the type bar and occupying an inoperative position can be pressed, by moving the type bar 4 in its longitudinal direction in relation to the carrier 1, into application against a printing support 7, a paper sheet 8 thereon and a ribbon 9 for printing the zero in conventional manner. Moving of the type bar 4 can be realized in a manner more precisely described in the following with the aid of a printing hammer 10 which is pivoted at 11 to the machine frame and can be swung down towards the type bar 4 occupying printing position in a printing stroke through a mechanism (not shown) of the type customarily employed in printing units of the type herein concerned. The setting register (not shown) and the rod 2 permit reciprocating the carrier 1 in a rectilinear path at right angles to the longitudinal direction of the type bars 4 for setting any one of the ten type bars 4 into printing position so that it is possible optionally to print any one of digits 09. Of course, there is a printing hammer 10 for each decade in the machine.

For each decade, a frame plate 13 having an elongate opening 14 is secured to a rod 12 associated with the machine frame. Extending along the upper edge of said opening 14 are two flanges or ribs 15, 16 which project from one side face of the plate 13 and are parallel or substantially parallel with the path of motion of the carrier 1. Said two ribs 15, 16 extend in the longitudinal direction of one another and their facing ends are located on either side of the printing position at a mutual distance insignificantly greater than the width of a head 17 on the upper end of each type bar 4. Mounted on a pivot 18 of the frame plate 13 is a coiled portion of spring wire, one end 30 of which is anchored to the plate 13 while the other end of the spring wire constitutes a rod-shaped elastically bendable portion 19 which extends along the rib 16 up to and slightly beyond the gap between the ribs 15 and 1-6 in printing position. The rodshaped spring portion 19 tends to bear against the undersides of the ribs 15 and 16 adjacent the ga between them, as will appear from FIG. 3, and has a piece 20 which in this position of the spring portion 19 penetrates between the facing ends of the two ribs 15, 16 which adjoin the printing position, in such a way that the piece 20 of the spring portion constitutes part of a guide which is substantially parallel with the path of motion of the carrier 1 and which is formed by the two ribs 15, 16 and the piece 20 of the spring portion 19. The type bars 4 engage this guide by means of a shoulder formed by therupper side wall of a transverse groove 21 in a lateral surface of the type bars, as will appear from FIG. 2. The shoulder is disposed at the underside of the head 17 on each type bar4.

During the movement of the carrier 1 the heads 17 of the type bars 4 thus slide along the upper side of the ribs 15, 1-6 and the spring piece 20, and the guide 15, 1'6, 20 holds the type bars in an elevated position in which the types 5 ofthe type bars take an inoperative position above the printing support 7 and a frame plate 22 adjacent to said support. When a type bar 4 has been set into printing position and the printing hammer 10 is caused to perform a printing stroke said hammer 10 presses the type bar 4 occupying the printing position against therprinting support 7, the head 17 of the type bar travelling downwards between the facing ends of the ribs 15, 16 against the action of the rod-shaped spring portion 19 which is swung down from the ribs 15, 16. When the printing hammer 10 is returned to elevated position the spring portion 19 restores the actuated type bar 4 to the elevated position shown in FIG. 1. During swinging of the spring portion 19 at the printing said spring portion actuates only the type bar 4 occupying printing position through the spring piece 20 because the spring portion 19 when swung down from the ribs 15, 1-6 moves between the plate 13 and the type bars 4 in the grooves 21 of the latter which are carried by the rib 15 and do not occupy printing position. The spring force counteracting the printing hammer 10 during printing will thusalways be equally large irrespective. of which typebar 4 performs the printing.

The carrier 1 is exactly guided in its path of motion in that it has on its end facing away from the rod 2 an upwardly directed lug 23 with a transverse groove in a lateral surface to engage and to be supported by the rib 15 inthe same way as the type bars 4, and a downwardly directed lug 24 engaging in a guide groove 25 in the frame plate 22.

The spring means 18-20, described in connection with FIGS. 1-3 may of course be replaced by some other yielding means of corresponding effect. FIG, 4 shows byway of example a lever 32 pivoted at 31 to the frame plate 13. A spring 34 tends to hold one end of the lever applied againstthe fixed rib 16. The lever 32 has a portion 33 which in this position penetrates between the ribs 15 and 16 and which acts in the same way as the 4 spring portion 20 described in connection with FIGS.

What I claim and desire tosecure by Letters Patent is:

1. A printing unit, comprising a printing support for supporting a sheet to be printed, stationary frame means, at least one type carrier reciprocable on said frame means in a definite path adjacent said printing, support, a plurality of type bars mounted in said carrier in a row in parallel side-by-side relationship to. partake inthe reciprocation of said carrier so as to be positioned .oneat a time in a printing position and movable in their longitudina'l direction in relation to said carrier transversely of the path thereof between an inoperative position spaced from said printing support and an operative position applied against saidprinting support, a printing type on each of said type bars on the endthereof adjacent said printing support, a first elongated guide means and a second elongated guide means stationarily mounted in longitudinal alignment on said frame means substantially in parallel with the path of said carrier and detining a gap between them for determining the printing position, a third guide means, mounting means onsaidframe for yieldingly holding said third guide meansin the printing position gap bet-ween said first and second guide means, engagement means on said type bars for engagement with said first, second, and third guide means to suppor t said type bars in their inoperative position du ring'reciprocation of said carrier, and a printing hammer movably mounted on said frame means for engaging any one of said type bars supported in the printing position gap by said third guide means and moving it to the operative position against the bias of said third guide means.

2. A printing unit asclaimed in claim 1, in which said first and second guide means each consist of a rib mounted on said frame means, and said engagement means is a shoulder on said type bars.

3. A printing unit as claimed in claim 2, in which said shoulder is formed by one side wall of a transverse groove in a lateral surface of said type bars. I p 4. A printing unit as claimed in claim 2 wherein said third guide means comprises a spring wire, said mounting means on said frame means holding a portion of said spring wire normally resiliently applied against at least one of said ribs, and a section of said spring wire penetrates between the facing ends of said ribs into the printing gap.

References Cited by the Examiner WILLIAM B. PENN, Primary Examiner, 

1. A PRINTING UNIT, COMPRISING A PRINTING SUPPORT FOR SUPPORTING A SHEET TO BE PRINTED, STATIONARY FRAME MEANS, AT LEAST ONE TYPE CARRIER RECIPROCABLE ON SAID FRAME MEANS IN A DEFINITE PATH ADJACENT SAID PRINTING SUPPORT, A PLURALITY OF TYPE BARS MOUNTED IN SAID CARRIER IN A ROW IN PARALLEL SIDE-BY-SIDE RELATIONSHIP TO PARTAKE IN THE RECIPROCATION OF SAID CARRIER SO AS TO BE POSITIONED ONE AT A TIME IN A PRINTING POSITION AND MOVABLE IN THEIR LONGITUDINAL DIRECTION IN RELATION TO SAID CARRIER TRANSVERSELY OF THE PATH THEREOF BETWEEN AN INOPERATIVE POSITION SPACED FROM SAID PRINTING SUPPORT AND AN OPERATIVE POSITION APPLIED AGAINST SAID PRINTING SUPPORT, A PRINTING TYPE ON EACH OF SAID TYPE BARS ON THE END THEREOF ADJACENT SAID PRINTING SUPPORT, A FIRST ELONGATED GUIDE MEANS AND A SECOND ELONGATED GUIDE MEANS STATIONARILY MOUNTED IN LONGITUDINAL ALIGNMENT ON SAID FRAME MEANS SUBSTANTIALLY IN PARALLEL WITH THE PATH OF SAID CARRIER AND DEFINING A 